Watercolour Washes Explained: Flat, Graded and Variegated

Almost every watercolour painting begins with a wash: a smooth layer of diluted colour spread across the paper. Skies, backgrounds, still-life tablecloths and distant hills all rely on one. Washes look simple, yet they trip up many beginners, because water does most of the work and you have to learn to trust it. Here are the three basic types and how to lay each one.

Before you start

Good preparation prevents most disasters. Use paper made for watercolour, ideally a weight of around 300 gsm, which resists buckling. Fix it to a board with masking tape or clips, then raise the top edge a few centimetres so that the liquid drifts gently downwards. Mix far more paint than you expect to need, because running out halfway across a sheet is the classic cause of hard, streaky lines. A large round or a flat wash brush holds plenty of water; if you are still building a kit, our guide to choosing your first brushes covers which shapes are worth buying.

The flat wash

A flat wash is an even colour with no change in tone.

1. Load the brush generously and draw a horizontal stroke across the top of the area.
2. A bead of paint will collect along the lower edge of that stroke.
3. Reload and pull a second stroke just beneath, so that it picks up the bead.
4. Continue downwards, working steadily and without going back over damp areas.
5. At the bottom, touch a nearly dry brush to the last bead to lift the excess.

Leave it flat to dry. Resist the urge to correct blemishes while the surface is wet, because that is what creates blooms and cauliflower edges.

The graded wash

A graded wash moves smoothly from dark to light, which makes it ideal for skies. Start as you would for a flat wash, but with each new stroke add a little more water to your mixture. The colour thins as you descend, and by the bottom it fades almost to white. Practise it with a single colour first, such as ultramarine or cerulean, and keep your strokes the same speed.

The variegated wash

A variegated wash blends two or more colours across the sheet. Begin with one colour at the top, switch to a second part-way down, and let them mingle where they meet. A warm yellow at the horizon melting upwards into soft blue is a favourite. Keep the paper tilted and the mixtures wet, so that the colours merge by themselves rather than being scrubbed together.

Troubleshooting common problems

• Streaks and hard lines: the wash started drying before you finished. Work faster or mix more paint.
• Blooms (cauliflower shapes): extra water was added into a half-dry area. Leave it alone or begin again once dry.
• Uneven pooling: the board was too flat, or the brush was overloaded at the end. Adjust the tilt and lift the last bead.
• Buckled paper: use a heavier sheet or stretch it beforehand.

Practise with purpose

Cut a sheet into six small rectangles and fill each with a different wash: two flat, two graded and two variegated. Do not worry about the results. Ten minutes of repetition builds the sense of timing that no amount of reading can give. When one works, make a note of the paper, the water ratio and the tilt, because those details are easy to forget.

Frequently asked questions

Should the paper be wet before I start? For a simple wash you can work on dry paper. Pre-wetting the sheet is a separate technique, useful for soft, blended effects, but it is harder to control at first.

How much water should I use? Enough that the paint flows and forms a bead, but not so much that it floods. You will find the balance with practice.

Can I fix a wash that has gone wrong? Sometimes you can lift colour with a clean, damp brush or a tissue, but the safest approach is to let the sheet dry completely and then decide whether to start again.